RN Nursing · Vital Signs · Practice question
The client asks what the bottom number represents in the blood pressure. Which description is accurate?
-
"It represents the pressure of veins bringing blood back to the lungs."
-
"It represents when the ventricles contract and push out the blood."
-
✓
"It represents when the ventricles relax and fill with blood."
-
"It represents how many times the heart beats per one full minute."
Answer & explanation
Correct: "It represents when the ventricles relax and fill with blood."
The bottom number in a blood pressure reading is the diastolic pressure. Diastole is the phase of the cardiac cycle during which the ventricles relax and passively fill with blood returning from the atria. During this phase, the pressure in the arterial system falls to its lowest point, which is what the diastolic number reflects. Understanding this distinction is foundational to interpreting blood pressure readings accurately. The top number, or systolic pressure, represents the peak pressure generated when the ventricles contract and eject blood into the aorta and pulmonary arteries — this corresponds to the option about ventricles contracting and pushing out blood. The option about veins bringing blood back to the lungs describes venous return to the pulmonary circuit, which is not what blood pressure measures — blood pressure refers to arterial, not venous, pressure. The option about how many times the heart beats per minute describes heart rate, which is measured in beats per minute and is entirely separate from blood pressure. A normal diastolic pressure is generally considered to be below 80 mmHg in adults, and understanding that it reflects the resting phase of the heart helps students differentiate it from systolic pressure and heart rate, two common points of confusion on examinations.
Practise Vital Signs questions
Work through full question sets with instant rationales, timed exams, and progress tracking.
Start practising freeRelated practice questions
- A nurse is obtaining an oxygen saturation on a client. Which of the following actions should the nurse take?
- A nurse is preparing to obtain an electronic blood pressure measurement on a client. Which of the following actions should the nurse plan to take?
- A nurse is collecting data about a client's circulatory system. Which of the following pulse sites should the nurse avoid checking bilaterally at the same time?
- A patient has an elevated temperature. The nurse assesses the patient and finds the skin flushed and very warm. The patient is oriented to person, place. time, and situation, and expresses severe fatigue. The most appropriate nursing action at this time would be to do which of the following?